Because the etiology of hypertension is largely unknown, the search for antihypertensive agents has been largely empirical. There currently are a number of commercially available agents, with widely varying mechanisms of action, employed in the management of hypertension. However, the search for new and improved agents continues because of the side effects of all known agents.
One approach in the search for improved hypertensive agents has been directed to the chemical modification of tetrahydrocannabinol (THC) in an effort to separate the anti-hypertensive properties of THC from the psychotropic and other pharmacological actions of THC. During the past decade, numerous derivatives were investigated, and while compounds having profound physiological effects have been discovered, to date attempts to provide an antihypertensive agent substantially devoid of psychotropic activity have been largely unsuccessful.
The present invention provides benzopyranopyridines which are useful as antihypertensive agents and which exhibit a low degree of psychotropic activity, unlike the benzopyranopyridines of U.S. Pat. Nos. 3,429,889; 3,576,798; 3,991,194; and Re. 29,196.